The Arms Race Is On!

Looking back over recent work and previous blog posts, there is more to report on the North Eastern Railway, Central Division signals. A lot of research and a lot of physical work has been taking place in order to get the arms themselves sorted.

As you may remember, or have noted from previous entries, the Central Division was unusual on the NER in NOT having slotted posts, with the arms inside. Very few bits of CD signals remain, and we were lucky enough to have a complete set of castings for the masthead. 

When it came to the length of the arms, however, things got a little trickier, since initially we did not have any drawings or specifications. Fortunately, at Kew, there are various documents and drawings. We were given a photograph of one of these drawings, which contained what we thought was a definitive answer: the arms are shown as being 4'6" long, beyond the end of the arm weight casting.

Having tried to source these in Cedar without any success (they are rather large...), we opted for using Tricoya, which is a modern product with very good longevity given its similarity in appearance, to MDF! These were supplied cut to size, leaving only the ends to shape to fit the castings. A template and router were used to achieve the correct fit, although each arm will need a minor adjustment to cater for casting projections within the pocket of the arm counterweight.

 

Just in time for the August Bank Holiday gala, we fitted the arm to the fixed stop signal at the limit of operations on the Tebay line. At this point we realised we had a bit of an issue. The arm did not return to the horizontal, danger, position, on its own! For the gala we secured it (it is a fixed signal, after all), but recognised the need for it to fail safe, and return to danger on its own. Our castings were slightly lighter than the originals, using a different grade of iron to reduce their fragility. We had no glazing in the spectacle, either. But the overall difference in weight was marginal, so we went back to photos of these signals, to see if there was something we might have overlooked...

It quickly became apparent that comparing our 'new' signal (despite following the drawings), had a longer arm than most photos showed! Could it be the case that the arms were found to be too long early on, and shortened Interestingly, the length of the arms seemed to vary, even on the same structure!

This can be seen on the gantry at KSE below.

Note the size of the main arms reading towards the station, compared to those for the junction!

Thanks for reading. Part 2 coming soon..